The above kind of inductance component conventionally has a planar component structure in view of miniaturization and reduction in height. The demand for reduction in height has increased recently.
Further, eddy current should be reduced in order to correspond to a shift of a switching frequency to ahigh frequency range. As a measure to perform the above, generally known is a method of forming a laminate structure including a magnetic body layer and an insulator layer. Such a technique is disclosed in JP-A-9-55316.
FIG. 9 shows a structure of a conventional inductance component disclosed in JP-A-9-55316. In FIG. 9, the inductance component has a magnetic body layer including Fe, a laminate film of an insulator layer made of nitride of positive element having specific resistance larger than that of the magnetic body and a coil conductor part for applying a magnetic field to the magnetic body layer. That is to say, the inductance component is formed from a magnetic body layer 111 formed in a laminating process, an insulator layer 112 made of AlN or the like and a planar coil part 113, which are piled into a laminate.
The number of layers of the magnetic body layer, however, should be increased or the film thickness of each layer of the magnetic body layer should be make thicker for the purpose of securing an inductance value necessary for the power supplying circuit. In the conventional forming method, required is a laminating process using a vacuum device such as vacuum evaporation and sputtering. This causes problems that investment in plant and equipment costs high and that mass-production is difficult in view of productivity.